WO2020207640A1

WO2020207640A1 - Tool for over-moulding and/or back-moulding a curved glass body, and method for over-moulding and/or back-moulding a curved glass body

Info

Publication number: WO2020207640A1
Application number: PCT/EP2020/053247
Authority: WO
Inventors: Maik STRUBE; Volker Wachenschwan; Christine SCHÜTZ; Wilma Dewald
Original assignee: Volkswagen Aktiengesellschaft
Priority date: 2019-04-11
Filing date: 2020-02-10
Publication date: 2020-10-15
Also published as: DE102019205203A1; EP3953137B1; EP3953137A1; CN113825610B; CN113825610A; US20220032514A1

Abstract

The invention relates to a tool (10) for over-moulding and/or back-moulding a curved glass body, the tool (10) having a first surface (11) for supporting the curved glass body. The tool (10) comprises a plurality of pins (13), the pins (13) each having a first end face (16) at a first end (15) of the pins (13), at least one section (12) of the first surface (11) being formed by the first end faces (16) of the pins (13). The pins (13) are mounted to be displaceable in their longitudinal direction (14) such that at least the section (12) of the first surface (11) can be adapted to a contour of the curved glass body.

Description

Tool for overmolding and / or overmolding a curved glass body and methods for overmolding and / or overmolding a curved glass body

The invention relates to a tool for overmolding and / or overmolding a curved glass body and a method for overmolding and / or overmolding a curved glass body.

3D free-formed glass bodies will play an increasingly important role in future vehicle interiors. Above all, they offer a very high level of scratch and chemical resistance, are very easy to coat or functionalize and can be integrated into elements such as displays, switches and lighting elements.

In order to be able to manufacture components with glass surfaces in processes suitable for large-scale production, processes are necessary that connect the glass with the corresponding connection elements in a short cycle time. The back-molding or overmolding of glass with plastic is an inexpensive and effective alternative to gluing.

However, the imaging accuracy of 3D-shaped glasses cannot be represented on a large scale with the level of accuracy in order to ensure that they nestle completely against an injection molding tool contour. In the prior art, cavities arise between the glass body and the tool into which the glass body is inserted. As soon as the plastic melt hits the glass, normally at very high pressures, it breaks when pressure peaks occur at certain points. This is particularly the case with flat deviations in shape and other bending radii than those provided in the tool. A workpiece that is uniaxially bent with a specified bending radius will have a hollow position if the radius is too small. If, on the other hand, it is too large, the leg of the bent piece no longer rests on the tool when the concave side rests on the tool. The greater the distance between the bending axis and the edge of the tool, the greater the effect.

The object of the present invention is to provide a tool and a method for overmolding and / or backmolding of a curved glass body, by means of which the overmolding or backmolding of the curved glass body is simplified, a breakage of the glass body can be avoided and therefore costs can be saved.

The above-mentioned object is achieved by a tool for encapsulating and / or backmolding a curved glass body, which tool has a first surface for placing the curved glass body on. The tool is designed in particular to produce a hybrid component comprising the curved glass body and preferably connection elements. In particular, the hybrid component is a hybrid component for a vehicle, in particular a motor vehicle. The tool includes a variety of pens. The pins each have a first end face at a first end, at least a portion of the first surface of the tool being formed by the first end faces of the pins. The pins are mounted so that they can be moved along their longitudinal direction, so that at least the section of the first surface can be adapted to a contour of the curved glass body. Due to the adaptability, the tolerances of the glass body are compensated and thus glass breakage is avoided.

The glass body is in particular a three-dimensional glass body, in particular a 3D free-form glass body. The glass body is not designed to be flexible. In particular, the glass body has a preferably constant thickness of 0.1 mm to 7 mm, in particular 0.3 mm to 4 mm, most preferably between 0.7 mm and 2 mm. In particular, the glass body is formed from soda-lime glass, aluminosilicate glass, borosilicate glass or lithium-aluminum silicate glass, preferably unhardened or chemically hardened, and / or laminated glass.

The curved glass body has in particular at least one bend. The section of the first surface of the tool is assigned in particular to a section of the glass body with a bend. In other words, the curved glass body is placed on the first surface in such a way that at least one bend is arranged in the first section of the first surface. The term “contour” of the curved glass body means, in particular, a shape of the surface of the curved glass body which faces the first section. In other words, the shape of the surface of the tool in the section can thus adapt to the shape of the surface of the curved glass body and, in particular, reproduce it with an accurate fit. The pins extend in particular in the longitudinal direction from a first end to a second end. The first end face is arranged at the first end. The first end faces together advantageously form a surface which forms the section of the first surface. The pins can advantageously be moved along their longitudinal direction in such a way that their position adapts to the contour of a glass body, specifically in such a way that the first end face of each pin rests on the surface of the glass body.

Because the pins are movably mounted and thus the section of the first surface can be adapted to a contour of an inserted, curved glass body, the tool is designed to adapt to complex glass geometries, in particular also to unknown contours, of a curved glass body. In particular, the tool thus has a tool surface which is flexible in shape and which can be precisely matched to the contour of a curved glass body. This avoids cavities and thus pressure peaks when overmolding and / or backmolding the curved glass body. Overall, a breakage of the glass body is thus avoided, with considerable costs being saved.

The choice of the size of the pins depends on the tolerances of the glass body and the complexity of the glass contour. The pins are preferably square pins. The pins can have a width which is at most 10 mm, in particular at most 8 mm, further preferably at most 6 mm. The width is to be understood as a dimension in a direction perpendicular to the longitudinal direction of the pins. Furthermore, both dimensions can have an abovementioned width in both directions perpendicular to the longitudinal direction. In particular, the pins can have a square cross section, so that they have the width mentioned above in two dimensions perpendicular to the longitudinal direction.

The particularly small design of the pins ensures better adaptability and reproducibility of the curved glass body in the section of the first surface. In other words, because they can be moved, the pins can fit snugly against the contour of the glass body, so that cavities are avoided during an injection molding process. In particular, the pins can be moved along their longitudinal direction in such a way that the surface formed by their first end faces forms a flush curved surface which, in particular, simulates the contour of the curved glass body in the section. For this purpose, the pins are in particular in rows and columns arranged in a row. In particular, the pins are arranged parallel to one another, their longitudinal direction corresponding in particular to a depth direction of the tool.

The pins are advantageously supported by means of springs and / or air cushions. In particular, the pins are each mounted at their second ends by means of a spring and / or an air cushion. As a result of this mounting, they are designed to be movable in the longitudinal direction. In particular, the springs can be preloaded. In particular, the springs are pretensioned by at least 0.5 mm, further preferably at least 1 mm, most preferably by about 2 mm.

Advantageously, the pins can be locked so that the pins, in a state adapted to the contour of the glass body, can serve as, in particular rigid, supports for the glass body during an injection molding process for overmolding and / or back molding. In other words, the pins can be locked so that moving in the longitudinal direction is no longer possible. After locking, the pins no longer give in longitudinal direction. The glass body can thus be supported conclusively and firmly, in particular during an injection molding process, so that breaks in the glass body are avoided.

The pins can advantageously be locked by means of lateral bracing. For this purpose, the tool has a clamping device, in particular in at least one direction perpendicular to the longitudinal direction, in particular in both directions perpendicular to the longitudinal direction, of the pins. The tensioning device has at least one tensioning screw which can press a piston in a lateral direction against the pins.

The tool is advantageously milled, in particular from steel.

In a further aspect, the invention relates to a method for overmolding and / or back-molding a curved glass body, the method comprising positioning the curved glass body on the first surface of the tool, at least a portion of the first surface through end faces of pins of the tool is formed. The positioning takes place in particular by means of a receiving device. For the temporary fixation of the glass body on the tool surface, a negative pressure can be applied in the tool. In particular, the section of the first surface is adapted to a contour of the glass body. To be precise, a position of the pins along their longitudinal direction is adjusted by moving the pins so that the first surface corresponds at least in the section to a contour of the glass body. The adaptation can in particular take place mechanically, in particular through the positioning of the pins which can be moved in the longitudinal direction, in particular by means of springs and / or air cushions. Due to the movable mounting of the pins, and in particular a pretensioning of the springs, the adaptation to the contour takes place automatically, so that not every individual pin has to be aligned manually. This makes the process much more effective.

Furthermore, the method comprises an injection molding method for overmolding and / or backmolding of the glass body. Furthermore, the injection molding process uses, in particular, a temperature of at least 150 ° C., furthermore preferably at least 175 ° C., most preferably at least 200 ° C., of the plastic melt. By means of the injection molding method, in particular a flowable material, in particular comprising or consisting of a plastic material (in other words a plastic melt), is introduced at the temperature mentioned above. The flowable material is in particular a thermoplastic elastomer. In particular, this has 10% to 50% glass fiber reinforcement. In order to avoid process-related pressure peaks, the plastic melt can be provided with a certain gas load, in particular by means of a chemical or physical blowing agent. The injection molding around and / or back molding is used in particular to connect the glass body to connecting elements.

In particular, the pins are locked after they have been adapted to the contour of the glass body and before the injection molding process is carried out, so that the pins serve as a support for the glass body during the injection molding process for overmolding and / or overmolding the glass body. This is done in particular by means of lateral bracing, which can preferably be done mechanically and / or hydraulically.

In particular, the method can include a presorting of glass bodies to be overmolded and / or backmolded, the presorting taking place according to their contour, so that a batch-wise adaptation to their contour can take place. In particular, an adaptation to the contour can be controlled in such a way that it takes place with each cycle and / or when the batch is changed. In particular, the method is designed to produce a hybrid component, in particular for a vehicle, which comprises the curved glass body. In particular, the method is carried out using a tool described above.

In particular, the tool is designed to carry out a method according to the invention.

Brief description of the drawings

The invention is explained in more detail with reference to the following purely schematic figures.

The figures show:

Figure 1 is a perspective view of a tool according to the invention;

Figure 2 is a perspective view of the pins of the tool of Figure 1;

FIG. 3 shows a plan view of the tool according to the invention from FIG. 1;

Figure 4 is a sectional view taken along line A-A of Figure 3; and

FIG. 5 shows a process diagram of a process according to the invention.

Embodiments of the invention

FIG. 1 shows a perspective view of a tool 10 according to the invention. The tool 10 has a first surface 11 for placing a curved glass body, not shown in the drawing, which is to be overmolded and / or backmolded. The tool 10 further comprises a multiplicity of pins 13. Each pin 13 has a first end 15 and a second end 18, only the first end 15 with its first end face 16 being visible in the figure. The pins 13 are arranged in rows 20 and columns next to one another. The first end faces 16 of the pins 13 form a surface 17 which forms a section 12 of the first surface 11 of the tool 10. The pins 13 are arranged such that their longitudinal direction 14 corresponds to the depth direction 42 of the tool 10. Furthermore, the tool 10 has a longitudinal direction 40 and a width direction 41.

The pins 13 can be moved in the longitudinal direction 14, so that their first end faces 16 can adapt to a contour of a glass body placed on the first surface 11. To the To lock pins 13 in a state adapted to the contour, they can be clamped by means of clamping devices 22. The clamping devices 22 each have at least one clamping screw 23. In detail, the tool 10 has a first clamping device 22a, which locks the pins 13 in the width direction 41 of the tool 10, and a second clamping device 22b, which locks the pins 13 in a longitudinal direction 40 of the tool 10.

FIG. 2 shows a perspective view of the pins 13 of the tool 10 of FIG. 1. The pins 13 extend in the longitudinal direction 14 from their first end 15 to the second end 18. At the first end 15, each pin 13 has the first end face 16. Furthermore, a width 13a of the pins 13 can be seen in FIG.

The pins 13 can be moved in the longitudinal direction 14 so that their position can be adapted to the contour of a glass body in such a way that the first end face 16 of each pin 13 rests on the surface of the glass body. The pins 13 are thus designed to form a flush, curved surface 17, the contour of which is adapted to the contour of the curved glass body. Overall, the pins 13 are arranged in seven rows 20 and 26 columns 21.

FIG. 3 shows a plan view of the tool 10 according to the invention from FIG. 1. It can be clearly seen how the first end faces 16 of the pins 13 form a section 12 of the first surface 11 of the tool 10. The section 12 is assigned in particular to a curved section of the curved glass body that is or is placed on the first surface 11.

FIG. 4 shows a sectional illustration along the line A-A of FIG. 3. It can be clearly seen how the pins 13 extend in the longitudinal direction 14 from their second end 18 to the first end 15. At the second end 18 there is arranged a spring 19, which is pretensioned and thus serves to make the pins 13 movable so that their position can be adapted to the contour of an applied glass body.

FIG. 5 shows a process diagram of a method 100 according to the invention for overmolding and / or backmolding of a curved glass body. The method 100 comprises the positioning 101 of the curved glass body on a first surface 11 of the tool 10. At least one section 12 of the first surface 11 is formed by the end faces 16 of pins 13 of the tool 10. For temporary fixation of the A negative pressure can be applied to the glass body on the tool surface in the tool.

The method 100 further comprises adapting 102 the section 12 to a contour of the glass body. For this purpose, the position of the pins 13 is adjusted by moving the pins 13 along their longitudinal direction 14, so that the first surface 11 corresponds at least in the section 12 to a contour of the glass body.

The method 100 also includes an injection molding method 104 for overmolding and / or backmolding the glass body. In the injection molding process 104, the tool 10 can be closed and a flowable molding compound, which is a plastic material (in other words a plastic melt), can be injected so that the molding compound is distributed in the free space formed by the closing of the material and completely fills the free space. to at least partially coat the glass body with the mass. In order to avoid process-related pressure peaks, the plastic melt can be provided with a certain gas load, in particular by means of a chemical or physical blowing agent.

In this way, a hybrid component can be produced that includes the curved glass body. Furthermore, the method can include locking 103 the pins 13 after their position has been adapted to the contour of the glass body, so that the pins 13 can serve as a support for the glass body during the injection molding process 104 and thus avoid breakage of the glass body.

List of reference symbols tool

first surface

Section of the first surface

pen

a width

Longitudinal direction of the pins

first end

first face

surface

second end

feather

line

column

Jig

a first jig

b second clamping device

Clamping screw in the longitudinal direction of the tool

Width direction of the tool

Depth direction of the tool 0 movement

1 Position the curved glass body on a first surface of a tool

2 Adapt the section to a contour of the glass body

3 Lock the pins

4 Injection molding process for overmolding and / or backmolding of the glass body

Claims

1. Tool (10) for encapsulating and / or back-molding a curved glass body, the tool (10) having a first surface (11) for placing the curved glass body on,

characterized in that

the tool (10) comprises a plurality of pins (13),

wherein the pins (13) each have a first end face (16) at a first end (15) of the pins (13),

wherein at least a portion (12) of the first surface (11) is formed by the first end faces (16) of the pins (13),

wherein the pins (13) are movably mounted along their longitudinal direction (14), so that at least the section (12) of the first surface (11) can be adapted to a contour of the curved glass body.

2. Tool (10) according to claim 1,

characterized in that

the pins (13) have a width (13a) which is at most 10 mm.

3. Tool (10) according to one of claims 1 or 2,

characterized in that

the pins (13) are lined up in rows (20) and columns (21) so that their first end faces (16) form a flush curved surface (17) when they are in a corresponding position in the longitudinal direction (14).

4. Tool (10) according to one of the preceding claims,

characterized in that

the pins (13) have a second end (18),

wherein the pins (13) are mounted at their second ends (18) by means of springs (19) and / or air cushions.

5. Tool (10) according to one of the preceding claims,

characterized in that the pins (13) can be locked,

so that the pins (13), in a state adapted to the contour of the glass body, can serve as a support for the glass body during an injection molding process for overmolding and / or back-molding the glass body.

6. tool (10) according to claim 5,

characterized in that

the pins (13) can be locked by means of lateral bracing.

7. The method (100) for overmolding and / or backmolding of a curved glass body, characterized in that

the method (100) comprises the following steps:

• Positioning the curved glass body on a first surface (11) of a tool (10),

wherein at least a portion (12) of the first surface (11) is formed by end faces (16) of pins (13) of the tool (10),

• Adapting (102) the section (12) to a contour of the glass body by moving the pins (13) along their longitudinal direction (14), and

• Carrying out an injection molding process (104) for overmolding and / or backmolding of the glass body.

8. The method (100) according to claim 7,

characterized in that

the adjustment (102) takes place mechanically.

9. The method (100) according to one of claims 7 or 8,

characterized in that

the pins (13) are locked (103) after they have been adapted to the contour of the glass body,

so that the pins (13) serve as a support for the glass body during the injection molding process (104) for overmolding and / or seating the glass body.